The present invention relates to a system for authenticating manufactured articles provided with magnetic markings and a method for marking such articles. In particular, the field of the invention relates to the detection of infringement of trademark rights for textile articles or leather goods. But it can also be related to that of the detection of self-sticking labels on any object (can, wine-bottle etc.).
Infringement is a problem of great concern for the manufactured products industry, and in particular the luxury goods industry. A certain number of means: visual marks, product engraving etc. have been developed to enable authentication of guaranteed origin products.
But, in the field of textile articles or leather goods, the introduction of a visual mark (hologram, laser engraving etc.) requires unpacking the article and carrying out a detailed visual examination to detect the marking. Furthermore, a marking which is not integrated into the article does not allow authentication of the article once it has been used, and is without its labels and its packaging.
It is also possible to carry out magnetic marking with the aid of a magnetically soft material. In fact, an elongated element in a substance of this type, when submitted to an alternating magnetic field high enough to reach saturation, generates harmonics which can be detected. It is also possible to detect a high frequency signal emitted when reversing the magnetisation of a magnetic material during application of an external magnetic field (Barkhausen effect), this effect being observed only on magnetic substances having a hysteresis cycle with high remanence and a weak coercive field.
As described in document referenced [1] at the end of the description, the use of ferromagnetic filaments to produce such a marking is known. This technique is used in many devices for electronic surveillance (EAS), such as those described in the document referenced [2]. In the field of electronic surveillance, the detection of an article is carried out in a non-cooperative manner: the magnetically soft material must be able to be detected without its carrier forcing himself to ease detection by a detection frame. Such a frame can be constituted of detection antennae monitoring an examination zone of large cross-section, in order to be able to detect over a sufficiently extensive zone, at the exit from a cash desk, for example, or at the exit from a shop.
On the other hand, such a co-operative magnetic detection, in which an individual possessing a device for detecting the presence of magnetically soft material, effectively tries to verify the existence of magnetic markers incorporated in an object, has not been greatly developed. Existing developments relate to systems for individual identification of objects, such as access badges, as described in documents referenced [3] and [4]. These systems are characterised on the one hand by an operation based on a precise spatial detection of a plurality of separate magnetic elements, and on the other hand by the pence on the object of a code allowing comparison of the information resulting from this detection, and from this code to certify the identity of the product. It is necessary to differentiate between these systems, which shall be called identification systems, inasmuch as they serve to ensure the identity of a single object, and the authentication system according to the invention, which serves to ensure the authenticity of the source.
In the devices according to prior art, ferromagnetic wires are sometimes used. When it concerns electronic surveillance, their diameter often exceeds 100 xcexcm. In electronic surveillance systems it is, in fact, necessary to have a sufficient quantity of material in order to allow detection in a fairly large examination region (of the order of 1 m3). Fire, since the strenth of the alternating magnetic field to which the public is submitted must be low, the wires must be able to react to a weak field, typically lower than 80 A/m.
The document referenced [8] describes a method and a rote detection sensor for used objects, with the aim of electronic surveillance. This method is different from prior art in that, as detection means, it utilises a physical property of amorphous or nano-crystalline metals; the variability of magnetic permeability with the magnetic field applied in the longitudinal direction of the element. Detection is thus no leer carried cut, as in prior art, with a magnetic field alone, but with a magnetic field and an electromagnetic field; an electromagnetic field for long range examination and a modulation field, a so-called variable magnetic field, for short range.
The aim of the invention is to produce a magnetic marking for manufactured articles, for example textiles or leather goods, which has the advantage of being invisible, which can be integrated during manufacture, and which remains present t the lifetime of these articles. A portable detection system of limited size then makes it possible to detect the presence or absence of magnetic marking, without it being necessary to proceed with a detailed examination of the product or unpacking it.
The invention relates to a system for authenticating manufactured articles provided with magnetic markings, by means of a device for detecting such markings, in which each marking apprises at least one amorphous ferromagnetic filament, the number n of these filaments being for example less than 10, of diameter less than 20 xcexcm provided with a glass sheath of thickness less than 10 xcexcm, characterised in that the detection device is a portable device for detecting such ferromagnetic filaments, and in that the ferromagnetic filament or filaments have a saturation field of at least 320 A/m.
These filaments have, for example a length comprised between 1 cm and 10 cm.
Advantageously, the portable device has a detection zone of a volume comprised between 10xe2x88x923 d3 and 1 d3. The filament or filaments have a total mass not exceeding 1 mg. Advantageously, the filaments comprise between 18 and 35% of Si+B, of cobalt or iron of more than 40% and possibly nickel ( less than 10%), and substances such as: Mo, Zr, Ge, Cr, Mn, V, Ti, C, with content less than 7%.
The wires can have a negative or positive magnetostriction.
The present invention also relates to a method for marking a manufactured article characterised in that at least one amorphous ferromagnetic filament of diameter lower than 20 xcexcm is integrated, provided with a glass sheath of thickness less than 10 xcexcm and having a saturation field of at least 320 A/m in a zone for this article, in such a way as to allow authentication of the latter by means of a detection device.
The filaments can be integrated by weaving or by stitching. These filaments can be inserted in a textile label, in a textile logo, or more generally in a predetermined part of the article. The filaments can be inserted by sewing, stitching, embroidery methods, or when the material is woven. The filaments can be incorporated in a textile thread, which can then be used during production of the material (as certain warp or weft threads), or used for sewing or embroidery operations, or for top stitching (in particular for leather goods).
Advantageously the authentication is carried out at several centimeters at most from the manufactured article.
The invention is clearly different from prior art systems, in particular for the following reasons:
The detection device according to the invention has an examination volume which is neither as big as electronic surveillance systems, nor as small as identification systems, which require precise positioning (of the order of mm) of several magnetic markers juxtaposed in a precise layout relative to each other.
The magnetic response of the marked article ensures that there is no detection by anti-theft detection frames (either the quantity is too small to ensure detection at distance, or the material saturation field is too strong to observe a significant non-linearity in the examination zone).
Each magnetic filament is inserted in the textile article during the manufacturing process, or incorporated into the label or the trademark logo, or into the label comprising the treatment recommendations. It is designed to be an integral part of the article over the whole of its lifetime, under normal conditions, contrary to electronic surveillance markers which can either be de-activated or taken off, but which in any case become useless or potentially carriers of false alarms after exiting the shop.
The glass sheath enclosing each magnetic filament is useful for protecting the magnetic material against corrosion by oxidation during the lifetime of the article, and in particular during washing or dry cleaning.
Each identification ferromagnetic filament is invisible to the naked eye; there is therefore no need to hide it.
Each ferromagnetic filament is flexible, comfortable, and does not involve any special restriction of use of a textile.
Each ferromagnetic filament is integrated into the article concerned by a textile method (weaving, embroidery, stitching etc.) and not, as in the case of electronic surveillance by a sticking or assembly type method etc. or, as in the case of badge production, by a plastifying method.
Relative to visual marks, the method according to the invention has the advantage of not requiring in-depth visual examination by the checking personnel, for example, by customs officers.
The method according to the invention does not need any manipulation intended to make a label or a control mark visible, since the authentication device is capable of detection within a limited volume (from 10xe2x88x923 dm3 to 1 dm3), but sufficient to avoid the necessity of unfolding the textile article or of separating articles arranged in piles.